Universal Plug and Play (UPnP) is a set of network protocols that is created to let electronic devices to detect and function within a networking environment. UPnP network allows the electronic devices to connect seamlessly and simplifies implementation of networks in home data sharing, communications, and entertainment and corporate environments. UPnP achieves this by defining and publishing UPnP device control protocols built upon open, Internet-based communication standards. Though it is widely known to connect devices using UPnP network protocols, the area of applications is still to be explored.
Further, an UPnP network architecture allows peer-to-peer networking of personal computers (PCs), networked appliances, and wireless devices. The architecture is a distributed and an open architecture based on established standards (e.g., UPnP telephony device/IP, UDP, HTTP and XML). The architecture may also support zeroconfiguration networking. A UPnP compatible device from an entity can dynamically join the UPnP network, may obtain an IP address, announce its name, convey its capabilities upon request or by default, and learn regarding presence and capabilities of other devices present in the network.
Further, UPnP devices can leave the network automatically without providing any unwanted state information. The UPnP network protocol provides discovery, control and creating event mechanisms as known to the person skilled in the art. A first step of discovery is enabled using Simple Service Delivery (SSD) protocol. All control messages are in the form of extended markup language (referred symbolically as XML). Creating events follows General Event Notification Architecture (GENA) protocol. Using these functions, the UPnP provides a real time availability and unavailability related information of the UPnP devices to the other devices in the network.
Furthermore, the UPnP network protocols provides telephony services for extending user experience in a home to access telephony services like messaging service, presence service, and call handling service. As analogous to UPnP Device Architecture (DA), telephony defines three kinds of devices, viz. a telephony server that provides messaging, and presence related services to the user, a telephony control point (UPnP telephony device) to initiate actions provided by the telephony server and a telephony client device (TC) for media related handling and providing input and output to or from the TS.
The UPnP telephony services enables a user to initiate/receive a call to any user outside the UPnP network using a Wide Area Network (WAN) calling technology like Voice Over Internet Protocol (VOIP) or other calling technologies. In spite of developments in the UPnP technology, there are still areas of application that are to be explored. One such area is the application of UPnP technology for managing voice mails in the UPnP network.